If they don't re-sign him they are hitting the restart button on their franchise, and they are in win now mode (not a tremendous amount of young talent outside of Dez Bryant, Morris Claiborne, and Tyron Smith).

If they do resign him- they have a guy that puts up good regular season numbers, but has never been one to make the plays when it mattered most. Furthermore, Romo holds a lot of bargaining power based on his regular season stats and the fact that he could walk after next year, and be guaranteed a contract with another team desperate for a qb (Cardinals, Browns, etc.)

Essentially the Cowboys are stuck, unless they want to roll the dice on a rookie qb in one of the next two drafts